Coolant pump

ABSTRACT

A rotary coolant pump for an internal-combustion engine has a coaxial annular centrifuge cavity and a scoop operable upon rotation of the pump to collect fluid coolant into the cavity under pressure through an inlet port located between radially outer and inner discharge ports of the cavity. The inner discharge port communicates with an annular seal for the pump journal and is isolated from high-velocity coolant flow within the cavity by a region therein of enlarged cross-sectional area which reduces the coolant velocity at a location spacing the inner discharge port from the inlet and outer discharge ports. Coolant and high-density particles such as core sand are thus discharged radially outwardly from the cavity by centrifugal force through the outer discharge port, whereas clean pressurized coolant flows through the inner discharge port to cool the seal.

ilnited States Patent [72] Inventors JereR.Lansinger [54] COOLANT PUMP 9 Claims, 4 Drawing Figs.

[52] US. Cl 415/112, 415/170 [51] Int. Cl F0ld 11/00 [50] Field ofSearch...., 415/110,

Primary Examiner-C. J. H usar Attorney-Talburtt and Baldwin ABSTRACT: A rotary coolant pump for an intemal-combustion engine has a coaxial annular centrifuge cavity and a scoop operable upon rotation of the pump to collect fluid coolant into the cavity under pressure through an inlet port located between radially outer and inner discharge ports of the cavity. The inner discharge port communicates with an annular seal for the pump journal and is isolated from highvelocity coolant flow within the cavity by a region therein of enlarged cross-sectional area which reduces the coolant velocity at a location spacing the inner discharge port from the inlet and outer discharge ports. Coolant and high-density particles such as core sand are thus discharged radially outwardly [56] Referencescited from the cavity by centrifugal force through the outer UNITED STATES PATENTS discharge port, whereas clean pressurized coolant flows 2,203,525 6/1940 Dupree,.lr 415/111 through h innerdischarge port tocool the seal. 2,352,636 7/1944 Jackman 4l5/11l m Y m j \llu J A. w i 2 ii //t Z I ll l j Z4 /A I! I J x Z l )7 r 7412/} /4 igll/j/j .0 I

i f j COOLANT PUMP BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to improvements in the coolant system for an intemal-combustion engine. It is conventional to cast portions of the engine around sand cores which are flushed out after the casting to leave ducts through which fluid coolant is circulated by means of a coolant pump. The latter commonly comprises a rotor joumaled on the engine and having a coaxial annular rotating seal in sliding engagement with a mating fixed seal to prevent loss of coolant. During high-speed rotation, coolant that would normally be in contact with the seal to cool the same, as required by reason of the sliding engagement between the rotating and fixed portions of the seal and other heat sources resulting from operation, is often separated from the seal by centrifugal force. In consequence the seal overheats and its effective life is materially shortened.

During slower speed operation, particles of residual core sand or other grit in the coolant work between the relatively moving parts of the seal and cause abrasion which likewise shortens the life of the seal. Not only must the seal be replaced, but if the damage is not detected early, which is frequently the case, loss of coolant can destroy the engine.

An important object of this invention is to provide an improved coolant system of the general type described whereby high-density particles such as core sand in the coolant are effectively and economically kept out of contact with the seal and a flow of clean pressurized fluid coolant is maintained in contact with the seal to cool the same during all operating conditions.

Another object is to provide simple and improved means in such a coolant system comprising a rotatable pump whereby the faster the pump rotates to increase the centrifugal force tending to separate the clean coolant from its cooling engagement with the seal, the greater will be the ram pressure of the scoop and subsequent flow of clean coolant into communication with the seal to cool the same.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

FIG. 1 is a fragmentary section through an automobile engine, taken along the axis of the coolant pump.

FIG. 2 is a view from one axial end of the pump, taken in the direction of the arrows substantially along the line 2-2 of FIG. 1.

FIG. 3 is a fragmentary view showing the high-pressure discharge port from the centrifuge cavity of the pump, taken in the direction of the arrows substantially along the line 3-3 of FIG. 1.

FIG. 4 is a fragmentary view through one of the scoops, taken in the direction of the arrows substantially along the line 4-4 of FIG. 2.

It is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

DESCRIPTION OFA PREFERRED EMBODIMENT Referring to the drawings, a fragmentary portion of an automobile engine comprising a housing for a coolant pump comprises in the present instance two parts 9 and 9a secured together by bolts 10. A pump rotor shaft 11 is joumaled at 12 within an extension of the housing part 9a. A pulley 13, driven by a belt (not shown) operatively connected with the engine crankshaft, has a central portion secured by bolts 14 to a hub 15 keyed coaxially to one end of shaft 11 for rotation therewith. The other end of shaft 11 is suitably secured to a rotor hub 16 to rotate the same, as for example by means of a press fit. The hub 16 is provided with an annular step 17 comprising a seat for a pair of axially spaced annular plates or discs 18 and 19. The inner periphery of the disc 18 comprises an annular flange 18a seated on the step 17 and underlying a similar flange 19a of the disc 19. The flanges 18a and 19a being suitably secured together and to the hub 16 for rotation as a unit therewith and with shaft 11.

A major portion of the disc 19 lies in a plane transverse to the axis of rotation and has a peripheral axially extending flange 19b overlying an annular blade carrying disc 20 secured flush against the radially outer portion of the disc 19 opposite the disc 18, FIG. 2. A plurality of rotor or pump blades 21 are lanced from the disc 20 at locations spaced uniformly around the axis of rotation and extend axially to impart centrifugal force induced radial flow to coolant in contact with the blades 21 upon rotation.

The peripheral portion 18b of disc 18 is secured flush with the adjacent outer peripheral portion of the disc 19 and diverges radially inwardly from the latter disc to a region 18c to provide a centrifuge chamber or cavity 22 having its maximum cross-sectional area at the region 180, which is approximately one-third of the radial distance from the inner flange 18a to the outer periphery 18b. The latter is dimpled at one or more locations 23a, FIG. 3, to provide a first set of restricted discharge ports 23 opening radially outwardly from the cavity 22.

At the region of the flange 18a a second set of restricted discharge ports 24 open radially from the cavity 22 at locations directly outwardly of a rotating annular L-section seal carrier 25 coaxial with the shaft 11. The carrier 25 is secured to the riser or step 17 for rotation therewith and carries a rotating coaxial rubbing seal 26 in sliding and sealing engagement with a mating fixed annular seal 27. The latter is urged axially to the right into sealing engagement with the seal 26 by a coil spring 28 disposed between a shoulder of seal 27 and an annular channel section spring retainer 28a, which in turn is supported by a fixed portion of the housing 90. Preferably, an annular boot or sleeve 29 of flexible material is also confined between one axial end of spring 28 and the retainer 28a and between the other axial end of spring 28 and the fixed seal 27, so that the entire seal assembly effects an annular fluid tight seal around the shaft 11 between the hub 16 and housing 9a to prevent leakage of fluid coolant axially along the shaft 11 to the bearing 12.

At each of a plurality of locations immediately radially inwardly of the pump blades 21, the disc 19 is apertured and bulged to provide a set of inlet ports 30 opening into cavity 22 oppositely from the direction of rotation indicated by the arrow, FIGS. 2 and 4, and a cooperating set of scoops or cams 31 diverging in the direction of rotation from the plane of the disc 19, so as to scoop fluid coolant in advance of the blades 21 and cam the coolant under pressure through the ports 30 into the cavity 22 during rotation.

The housing 9 provides portions of a conduit for circulating coolant through the engine and an air-cooled radiator (not shown) whereby engine heat is dissipated by the latter in accordance with conventional practice. The recirculating coolant enters the pump housing 9 at low pressure via port 32, flows around a radially inwardly directed annular baffle 33 integral with the housing 9, then flows axially through a central annular pump inlet 34 defined by the inner periphery of the baffle 33 and rotor hub 16, as indicated by the arrows, FIG. I. The baffle 33 conforms closely to the contour of the axially outer edges of the rotor blades 21 and cooperates with the rotor disc 19 to provide an annular guide or flow passage from the pump inlet 34 to the pump outlet 35 through which pressurized coolant is discharged by centrifugal force.

It is apparent that by virtue of the scoops or earns 31 opening in the direction of rotation and defining the trailing edges of the inlet ports 30, the faster the pump rotates, the greater will be the resulting pressure of the coolant within the cavity 22. Where desired, the inlet ports 30 and earns 31 may be arranged and designed with respect to the impeller blades 21 to effect a pressure within cavity 22 greater than the discharge pressure of the pump at port 35.

As the coolant enters the cavity 22 via inlet ports 30, high density particles such as core sand suspended within the coolant is thrown by centrifugal force radially outwardly through the discharge ports 23, along with a portion of the coolant. If the pressure within cavity 22 is greater than the pump discharge pressure, the ports 23 may discharge at any location into the high-pressure coolant downstream of the port 35. In the present instance, the pressure within cavity 22 need not exceed the pump outlet pressure because the coolant flow through ports 23 discharges into the high-velocity discharge flow from the pump and is carried along with this flow by venturi or aspirator action.

It is also to be noted that as the coolant enters cavity 22 via ports 30 at the region of maximum cross-sectional area indicated at 18c, the coolant flow velocity will be a minimum, so that the centrifugal force induced radial outward flow of sand particles and the like will not be significantly influenced by turbulence within the coolant. Accordingly, the coolant radially inwardly of the ports 30 and the region 180 of maximum cross-sectional area will be shielded from the high-velocity flow within the radially outer portion of cavity 22 and will be free of high-density particles. Clean coolant will thus be discharged under pressure through ports 24 into communication with the seal 26,27 to cool the same. Inasmuch as the pressure within cavity 22 increases with increasing rotational velocity as aforesaid, as the coolant immediately outwardly of the seal 26,27 flows from the latter by centrifugal force, this coolant is replaced by a continuous stream of comparatively cool fresh coolant.

Also in the latter regard, the disc 18 cooperates with the adjacent wall of housing 9a to provide a coolant flow path 36 from ports 24, along the seal 26,27, and thence radially outwardly through an opening 37 adjacent the outer periphery of the disc 18 at the junction of the housing members 9 and 9a.

We claim:

1. In a coolant system for an internal-combustion engine,

rotatable pump means for receiving low-pressure fluid coolant and discharging the same at higher pressure upon rotation of said pump means,

a centrifuge cavity carried by said pump means for rotation therewith and having inlet port means,

sealing means comprising annular sealing means carried coaxially by said pump means for slidably engaging fixed sealing means,

cam means carried by said pump means for rotation therewith and associated with said inlet port means for engaging and camming a portion of said coolant exteriorly of said cavity into the latter under pressure through said inlet port means upon said rotation,

said cavity having first discharge port means and defining a centrifugal force induced flow path from said inlet port means to said first discharge port means for discharging coolant and high-density particles from said cavity upon said rotation,

said cavity having second discharge port means remote from said centrifugal force induced primary flow path and communicating with said sealing means for discharging pressurized coolant from said cavity to said sealing means to cool the latter.

2. In the combination according to claim 1, said first and second discharge port means opening from the radially outer and inner portions respectively of said cavity and said inlet port means opening into said cavity at a location radially between said first and second discharge port means.

3. In the combination according to claim 2, said cavity extending annularly coaxially around the axis of rotation, and said first and second discharge port means comprising ports through the radially outer and inner walls respectively of said cavity.

4. In the combination according to claim 1, said inlet and first dischar e port means being located radially outwardly of said second ischarge port means, and means for isolating said second discharge port means from high-velocity flow in said primary flow path comprising a region of said cavity of enlarged cross-sectional area effecting a reduced rate of flow velocity thereat and spacing said second discharge port means from said inlet and first discharge port means.

5. In the combination according to claim 1, said system defining conduit means for circulating said coolant and having a pump inlet for supplying said low-pressure coolant to said pump means and also having a pump outlet for receiving the higher pressure coolant discharged from said pump means, said cam means being located adjacent said pump inlet to engage and cam said low-pressure coolant into said cavity.

6. In the combination according to claim 5, said pump means comprising impeller means for discharging said higher pressure coolant radially by centrifugal force.

7. In the combination according to claim 1, said system defining conduit means for circulating said coolant and having a pump inlet for supplying said low-pressure coolant to said pump means and also having a pump outlet for receiving the higher pressure coolant discharged from said pump means, said system defining a seal cooling flow path radially outward of said annular sealing means and defined in part thereby and communicating with said second discharge port means to receive coolant discharged therethrough from said cavity and also communicating with said conduit means at a location downstream of said second discharge port means.

8. In the combination according to claim 1, said system defining conduit means for circulating said coolant and having a pump inlet for supplying said low-pressure coolant to said pump means and also having a pump outlet for receiving the higher pressure coolant discharged from said pump means, said cavity extending annularly coaxially around the axis of rotation, and said first and second discharge port means comprising ports through the radially outer and inner walls respectively of said cavity, said pump means comprising impeller means for discharging said higher pressure coolant radially by centrifugal force and duct means connecting said first discharge port means with said conduit means at a location downstream of said first discharge port means.

9. In the combination according to claim 8, said inlet port means being located radially outwardly of said second discharge port means, and means for isolating said second discharge port means from high-velocity flow in said primary flow path comprising a region of said cavity of enlarged crosssectional area effecting a reduced rate of flow velocity thereat and spacing said second discharge port means from said inlet and first discharge port means. 

1. In a coolant system for an internal-combustion engine, rotatable pump means for receiving low-pressure fluid coolant and disCharging the same at higher pressure upon rotation of said pump means, a centrifuge cavity carried by said pump means for rotation therewith and having inlet port means, sealing means comprising annular sealing means carried coaxially by said pump means for slidably engaging fixed sealing means, cam means carried by said pump means for rotation therewith and associated with said inlet port means for engaging and camming a portion of said coolant exteriorly of said cavity into the latter under pressure through said inlet port means upon said rotation, said cavity having first discharge port means and defining a centrifugal force induced flow path from said inlet port means to said first discharge port means for discharging coolant and high-density particles from said cavity upon said rotation, said cavity having second discharge port means remote from said centrifugal force induced primary flow path and communicating with said sealing means for discharging pressurized coolant from said cavity to said sealing means to cool the latter.
 2. In the combination according to claim 1, said first and second discharge port means opening from the radially outer and inner portions respectively of said cavity and said inlet port means opening into said cavity at a location radially between said first and second discharge port means.
 3. In the combination according to claim 2, said cavity extending annularly coaxially around the axis of rotation, and said first and second discharge port means comprising ports through the radially outer and inner walls respectively of said cavity.
 4. In the combination according to claim 1, said inlet and first discharge port means being located radially outwardly of said second discharge port means, and means for isolating said second discharge port means from high-velocity flow in said primary flow path comprising a region of said cavity of enlarged cross-sectional area effecting a reduced rate of flow velocity thereat and spacing said second discharge port means from said inlet and first discharge port means.
 5. In the combination according to claim 1, said system defining conduit means for circulating said coolant and having a pump inlet for supplying said low-pressure coolant to said pump means and also having a pump outlet for receiving the higher pressure coolant discharged from said pump means, said cam means being located adjacent said pump inlet to engage and cam said low-pressure coolant into said cavity.
 6. In the combination according to claim 5, said pump means comprising impeller means for discharging said higher pressure coolant radially by centrifugal force.
 7. In the combination according to claim 1, said system defining conduit means for circulating said coolant and having a pump inlet for supplying said low-pressure coolant to said pump means and also having a pump outlet for receiving the higher pressure coolant discharged from said pump means, said system defining a seal cooling flow path radially outward of said annular sealing means and defined in part thereby and communicating with said second discharge port means to receive coolant discharged therethrough from said cavity and also communicating with said conduit means at a location downstream of said second discharge port means.
 8. In the combination according to claim 1, said system defining conduit means for circulating said coolant and having a pump inlet for supplying said low-pressure coolant to said pump means and also having a pump outlet for receiving the higher pressure coolant discharged from said pump means, said cavity extending annularly coaxially around the axis of rotation, and said first and second discharge port means comprising ports through the radially outer and inner walls respectively of said cavity, said pump means comprising impeller means for discharging said higher pressure coolant radially by centrifugal force and duct means connecting said first discharge port means with said conduit means at a location downstream of Said first discharge port means.
 9. In the combination according to claim 8, said inlet port means being located radially outwardly of said second discharge port means, and means for isolating said second discharge port means from high-velocity flow in said primary flow path comprising a region of said cavity of enlarged cross-sectional area effecting a reduced rate of flow velocity thereat and spacing said second discharge port means from said inlet and first discharge port means. 